Subject: Diameter growth

Name: Gary Dixon

Date: 02/16/18

Variants affected: Central States (CS) and Lake States (LS)

Description: In 2017, the large tree diameter growth equation in these two variants was replaced with an
             equation developed through cost share agreement number 10-CS-11132425-258 with Michigan
             Technological University dated October 2012. Implementation of this equation was not done correctly
             resulting in errant calibration of the large tree diameter growth model, and errant diameter growth
             estimates for all trees greater than 1.5" in diameter. These errors have been corrected.
             

Impact on users: Users of the CS and LS variants should get a new executable.

Files:
cs/src  blkdat.f  The $ID date-of-revision line was implemented. The large-tree diameter growth equation error
                  term for species 6 (Other Softwood Species (OS)) was changed from 0.0 to 0.63965. This species
                  uses the eastern white pine large-tree equation, and 0.63965 is the error term associated with
                  that equation. 

        dgdriv.f  The unused variable DNSNYY was deleted. The mixed-mode arithmatic in the setting of
                  variable ISI was corrected. The breakpoint diameter between the large- and small-tree models 
                  was changed from 3.0" to 5.0" to correspond with the new large-tree diameter growth equation. 
                  The corresponding comment statement was changed to reflect the new breakpoint diameter.
        
           dgf.f  All variables and calculations assoicated with computing BAL based on statistics for trees with
                  diameters 5.0 inches and larger were taken out, and the BAL calculation was replaced with the
                  one-line standard BAL calculation. In addition to simplifying the code, this also corrects a
                  problem with inconsistent percentile values between trees with diameters less than 5.0 inches
                  and trees with diameters greater than or equal to 5.0 inches. Numerous other changes were made 
                  in this subroutine pertaining to general code modernization but have nothing to do with 
                  its execution.
           
        regent.f  The unused variable MODE9 was deleted. The range of diameters over which the small-tree
                  growth estimates are weighted with the large-tree growth estimates, to ensure a smoother
                  transition between the two models, was changed from (1.5", 5.0") to (3.0", 5.0") to correspond with 
                  the new large-tree diameter growth equation. The unused statement label 95 was removed. The mixed 
                  mode setting ICR(I)=(CR*100.0)+0.5 was changed to ICR(I)=NINT(CR*100.0). The variable D in the second
                  call to subroutine BALMOD was undefined, and replaced with DBH(I).


ls/src  blkdat.f  The $ID date-of-revision line was implemented. The large-tree diameter growth equation error
                  term for species 44 (Commercial Hardwood Species (CH)) was changed from 0.0 to 0.74594. This
                  species uses the large-tree equation associated with black walnut and butternut, 
                  and 0.74594 is the error term associated with those species. 

        dgdriv.f  The breakpoint diameter between the large- and small-tree models was changed from 3.0" to 5.0" 
                  to correspond with the new large-tree diameter growth equation. The corresponding comment
                  statement was changed to reflect the new breakpoint diameter.
        
           dgf.f  All variables and calculations assoicated with computing BAL based on statistics
                  for trees with diameters 5.0 inches and larger were taken out, and the BAL calculation was replaced
                  with the one-line standard BAL calculation. In addition to simplifying the code, this also corrects
                  a problem with inconsistent percentile values between trees with diameters less than 5.0 inches
                  and trees with diameters greater than or equal to 5.0 inches. Numerous other changes were made 
                  in this subroutine pertaining to general code modernization but have nothing to do with 
                  its execution.
           
        regent.f  The unused variable MODE9 was deleted. The range of diameters over which the small-tree
                  growth estimates are weighted with the large-tree growth estimates, to ensure a smoother
                  transition between the two models, was changed from (1.5", 5.0") to (3.0", 5.0") to correspond with 
                  the new large-tree diameter growth equation. The unused statement label 95 was removed. The mixed 
                  mode setting ICR(I)=(CR*100.0)+0.5 was changed to ICR(I)=NINT(CR*100.0). The variable D in the second
                  call to subroutine BALMOD was undefined, and replaced with DBH(I).

tests/FVSCS
  cst01.sum.save  This file was updated to reflect these changes.

tests/FVSLS
  lst01.sum.save  This file was updated to reflect these changes.
